Oops. I forgot one crucial part of this. Steem user's need to be able to vote on which Certificate Authorities they trust, similar to how they can vote for what Delegates they prefer.

The certificates issued from the CAs with the most votes would be weighted more than certificates issued from CAs with less votes in the SP/certificate weighting calculation. This helps prevent people from setting up fraudulent CAs to certify their sock puppets, gives the community a way to "revoke" the certificates a corrupt CA has issued, and also gives the ability to make sure that a respected and trustworthy individual's certificates are more valuable than others that may be less respected or trustworthy.